Next year will see no return to the romance of the rose garden politics of the Coalition partners' early cohabition.

Which is just as well, since the illusion couldn't last.

But the two parties won't go their separate ways, either. Nick Clegg would lose out in any early election. And David Cameron wouldn't win one outright (even if he wanted a snap poll, which he doesn't). The eight or so point poll lead over Labour he needs for an overall majority doesn't exist.

The main Conservative frustration with the Liberal Democrats – now that the Prime Minister has pushed EU policy in a Euro-sceptic direction – is their holding-back of pro-growth measures. Consider Vince Cable's hostile reaction to the Beecroft Report and reactionary stance on the 50p rate. Or the higher costs to business and consumers provoked by Chris Huhne's push for green targets and wind turbines.

The Liberal Democrat frustration with the Conservatives doesn't seem to me to be so much about policy as about ownership. A few Government Departments contain Tory Ministers only, at least as far as the Commons is concerned. None have a majority of Liberal Democrat Ministers. This arrangement reflects the Parliamentary arithmetic. But it leaves the junior partner short of icons to point to – symbols of what the party is achieving in government.

The wins that it champions are too puny to grab voters by the lapels. For example, the raising of the income tax threshold is too small an element in the overall tax mix to seize attention. So instead, the Liberal Democrats have taken to defining themselves by what they're stopping – or trying to – rather than what they're playing a part in achieving. They were against Andrew Lansley's original health plans. They are still against plans for a British Bill of Rights.

And they're against support for marriage, as Clegg reminded us recently. His move was intended to counter the narrative of a strong Prime Minister and a weak Deputy. It simply reinforced it.

A possible route round the problem would be to make the spring reshuffle a grand bargain between the two parties.

The Liberal Democrats would gain a majority of Ministers in some non-economic Departments, in order to give them some big wins that voters would remember. Tim has previously suggested health. I would add the Environment. Plus perhaps the Scottish Office. And – if necessary (big gulp) – local government.

But in return, the Conservatives would win control of all the main economic-related departments.

Tory domination of the Treasury team would continue. Vince Cable would be winkled out of Business and Chris Huhne from Climate Change (assuming, of course, that he's still in place).

In other words, some of the main obstacles to strong growth policies would be dismantled at a stroke. No, I'm no happier about such a plan than you are. Or Liberal Democrats would probably be, either. But the choice is either radical change or the status quo. Either real Liberal Democrat ownership of part of the government and full Conservative control of economic policy, or the present toing and froing.